The present invention relates to apparatus for charging preheated coal into coke oven chambers arranged in a battery from a coal bunker disposed above the battery and large enough to contain sufficient coal to charge at least one oven chamber.
Coke is produced from coal in coke ovens which usually consist of a number of oven chambers arranged in a battery or batteries. In many cases, it is desirable to preheat the coal before charging it into the oven chambers to reduce the length of the coking time and thus increase the productivity of the coke oven. This results in a substantial cost reduction in many cases where the saving in costs of the coking plant outweighs the operating costs and capital cost of the necessary coal preheating plant. There are also certain types or grades of coal whose coking properties are improved if they are preheated before being charged into the coke oven. This frequently makes it possible to use non-coking grades of coal. Thus, the use of preheated coal is frequently desirable.
There are, however, certain problems in charging preheated coal into a coke oven. Most coal preheating processes are essentially continuous processes which supply a continuous stream of preheated coal. The normal horizontal coke ovens, however, operate intermittently in a batch-type process and must be charged with coal at more or less regular time intervals. With a continuous supply of preheated coal, therefore, a storage bunker must be provided for the coal which has sufficient capacity to contain the necessary amount of coal for charging at least one of the coke oven chambers, and preferably several chambers. The coal must then be conveyed in batches from the bunker to the individual oven chambers in the correct predetermined quantities for charging the chambers. This must be done in a manner to protect the preheated coal from the air and to minimize the time required for charging. It is especially important to keep the charging time as short as possible since charging preheated coal into the heated coke oven intensifies the evolution of charging gases, and the excess pressure in the oven chamber, which always accompany the charging of coal.